Atrain-car is to a train as a is to a polymer and a molecule is to a

, you!

(it has to do with macromolecules)

the awnser is d i think

the atmospheric gas that forms a mild acid when dissolved in water is called carbon dioxide. the correct answer is a. 2.) chemical weathering would cause an inscription on a marble headstone to become harder and harder to read over time.

well, i believe that the answer is 2. : 3